REVENUE AND CONTRACT ACQUISITION COSTS - Revenue Disaggregated by Types and Geography (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Total revenue	$ 1,099.5	$ 973.7
Instruments and accessories
Disaggregation of Revenue [Line Items]
Total revenue	617.5	552.3
Systems
Disaggregation of Revenue [Line Items]
Total revenue	283.3	247.5
Services
Disaggregation of Revenue [Line Items]
Total revenue	198.7	173.9
U.S.
Disaggregation of Revenue [Line Items]
Total revenue	781.6	691.6
U.S. | Instruments and accessories
Disaggregation of Revenue [Line Items]
Total revenue	444.4	407.4
U.S. | Systems
Disaggregation of Revenue [Line Items]
Total revenue	198.8	160.7
U.S. | Services
Disaggregation of Revenue [Line Items]
Total revenue	138.4	123.5
Outside of U.S. (“OUS”)
Disaggregation of Revenue [Line Items]
Total revenue	317.9	282.1
Outside of U.S. (“OUS”) | Instruments and accessories
Disaggregation of Revenue [Line Items]
Total revenue	173.1	144.9
Outside of U.S. (“OUS”) | Systems
Disaggregation of Revenue [Line Items]
Total revenue	84.5	86.8
Outside of U.S. (“OUS”) | Services
Disaggregation of Revenue [Line Items]
Total revenue	$ 60.3	$ 50.4